Caster



J. BOWEN June 8 1926.

CASTER June 8 1926.

J. BOWEN '.cAsTER Filed Deo. 19, 1924 2 Sheets-Sheet 2 f4 l l j-/ 6 Ayr 79 Y /5 j@ 6 $2 72 IWW@ z2 52km f Patented June 8, 1926.

UNITED STATES PATENT oF FI CE.

JAMES BOWEN, OF MANHEII, PENNSYLVANIA, ASIGNOB TO` BOND FOUNDBY & HA-

cHINn conm, or yann.

PENNSYLVANIA, A CORPORATION OI PENNSYL- CASTEL Application ilcd December 19, 19M. Serial No. 756,920.

The object of this invention is to improve the construction of casters, particularly ada ted for use on trucks.

asters of this type must' be substantial and so designed that they will swivel readily under heavy loads, while supporting the loads properly at all times. v

In the accompanying drawings: Fig. 1 is a slde view, showing the upper l portion of the caster in section;

Fig. 2 is a sectional plan view on the line 2 2, Fig. 1; Y

Fig. 3 is a front view of the caster;

Fig. 4 is a detached side view of one of the rollers;

Fig. 5 is a perspective view of one of the rollers;

Fig. 6 is a detached sectional v1ew of the base of the caster Fig. 7 is a detached sectional view of the body portion of the swivel section of the caster;

Fig. 8 is a plan view of one-half of` e retainer for the rollers; and

Fig. 9 is a sectional perspective view of a portion of the retainer.

The base member 1 of the caster 1s p erforated,l as shown by dotted lines, to receive bolts, which attach the base to the frame of a truck. The base has a central de ression 2, in which is a tapered openin 3. epending from the periphery o the ase 1s a deep lflan e 4, which encloses the body portion 5 of t e swivel vmember 6 of the caster. The member 6 is forked, as. at 7, to receive a supporting wheel 8, which is mounted on a sleeve 9 that is carried by a bolt 10. The body portion 5 has a tapered. projection or boss 12, which extends into the tapered opening 3 in the base 1. A king bolt 11 extends A through' an opening in the taperedv portion 12. The shank ofthe bolt is squared at 13 under the head 14 and ts a squared portlon of the said opening so that the bolt turns with the swivel portion 6 of the caster. The head 14 of the bolt is located in the depression 2 of the base 1 and a washer 15 1s located under the head and extends over the base of the depression, holding .the swivel portion 6 to the base 1. On the threaded end of the bolt is a nut 16. This construction prevents the king bolt from becoming loose.

From the foregoing description, itwill-be clear that the swivel member can move with respect to the base member about a vertical -,way 24 on the -base axisl f- One* of these members vis provided with a-single annular raceway 24 and the other of the members is rovided with two annular `raceways- 17 and) 18 spaced apart.- Preferably thel single raceway is lon the base member and the two spaced raceways are on the swivel member, but I do not necessarily limit myself in this respect. In accordance with my invention the aforesaid raceways are so shaped and so located that their lines of intersection with a verticalradial plane can be extended a considerable dist-ance past the swivel axisvwithout intersecting each other. This is illustrated in Fig. l wherein the line -w-Jw extending through the raceway on. the lbase member and the line y-y extending through thetwo raceways on the swivel -member 1ntersect each other at a yond the vertical swivel axis. y

`-' Located between the two plates and engaging the respective raceways are bearing rollers 20. Each roller has a relativel central portion 23 engaging the sin e racemem er and as two trunnions'21 and 22 respectively engaging the two raceways 17 and 18 on the swivel member. It will be observed that the porlarge msl tion- 23 of the roller extends into the groove 19 between the' two raceways 17 and 18 and is adapted t`o travel freely in this groove without contacting with the swivel member.

Preferably the raceway 24 is flat and the raceways 17 and-18 are beveled. In this case the line w-'w is horizontal and the line y-g is inclined so as to intersect at the point w the horizontal plane extending.

through the axes of ,the'rollei-s. This point of intersection is at the vertical swivel axis.

The two trunnions. 21 and 22 are tapered uniformly and in the same direction so asto give true rolling contact with the raceways 17 and..18. When the several raceways are shaped and located as described the central portion 23 of each roller is cylindrical, being of uniform diameter throug out so as to enga e the flat raceway 24.

ith the construct-ion described the tapered trunnions cause the rollers to travel in a circular path inasmuch as they have true rolling contact with their respective raceways. A true theoretical rolling contact is not secured at the raceway 24 and this is avoided in order to eliminate, or at least minimize, the tendency which would otherwise existl for the load to gradually crowd the rollers outward. It will be obvious that as the angle between the line w-fw and jl/y is reduced this tendency for the rollers to work outward is correspondin ly reduced.-

In order to prevent4 any possi le endwise movements of the rollers annular flanges 29 and 30 are provided on one of the members preferably on the swivel member as shown. The ends of the rollers are made convex so that the friction on the flanges 29 and 30 is webs 26 and 27 which extend bet-Ween the` turnnions of the rollers as shown.

A ball bearing is preferably provided to take the side thrusts on the caster. The iuner raceway 3'1 is formed on a depending flange of the base that surrounds the o ening 3, and an outer raceway 32 is forme on the inner surface of the annular raceway 18 of the body portion 5. lBalls 33 are located between the two raceways, as shown, and take the lateral thrust of the caster. The

peri heral flange 4 of the base 1 encloses the i for lubricant, as

mec anism, making the caster substantially dust proof.

The annular channel 19 forms a receptacle does the space occupied h the balls. The channel can be supplied wit grease, or other lubricant, throughl a valved cu 34.

claim: V 1. The combination in a caster, of a suporting wheel, a base member, a swivel membei' connected with the wheel and movable with respect to the base member about a vertical axis, the base member being provided with a flat annular raceway and the swivel member being provided with two spaced beveled annular raceways, a series of rollers between the two members, each roller having a relatively large central cylindrical portion enga ing the first said raceway and travellin reel between the second said raceways au also aving two trunnions respectively engaging the second raceways and so tapered as to have true rolling contact therewith, and a spacer for the rollers comprising a flat plate located between the roller trunnions and the base member and have apertures through which the central parts of the rollers project.

2. The combination in a caster, of a supporting wheel, a' base member, a swivel 4member connected with the wheel and movable with respect to the base member about a vertlcal axis, the base member being pro- `vided with a fiat annular raceway and the swivel member being provided with two spaced beveled annular raceways, a series of rollers between the two members, each roller having a relatively large central cylindrical portion engaging the first said raceway and travelling freely vbetween the second saidraceways and also having two trunnions respectively engaging the second said raceways and so tapered as to have true rolling contact therewith, and a spacer for the rollers comprising a flat plate between the roller trunnions and the base member and have apertures through which the central parts of the rollers project, and also comprising two series of depending webs respectively located between the inner trunnions and between the outer trunnions.

3.,'l`he combination in a caster, of a supporting wheel, a base member, a swivel member connected with the wheel and movable with respect to the base member about a vertical axis, the base member being provided With a fiat annular raceway and the swivel member being provided with two spaced beveled annular raceways, a series of rollers between the two members, each roller having a relatively'large central cylindrical portionv engagmg theI first said raceway and travelling freely between the second said raceways and also having two trunnions respectively engaging the second z said raceways and so tapered as to have true 100 rolling contact therewith, and inte al annular flanges on one of the memgers engaging the ends of the trunnions to prevent endwise movement of the rollers.

4. The combination in a caster, of a supporting wheel, a base member, a swivel member connected with the wheel and movable with respect to the base member about a vertical axis, the base member being provided with a flat annular raceway and the swivel member being provided with two spaced beveled annular raceways, a series of rollers between the two members, each roller having a relatively large central cylindrical portion engaging the first said raceway'and 115 travelling freely between the second said raceways and also having two trunnions respectively ,engaging the second said raceways and so ta ered as to have true rolling contact therewith, integral annular flanges on one of the members engaging the ends to the trunnions to prevent endwise movement of the rollers, and a` spacer for the rollers comprising a Hat plate located between the roller trunnions land the base member and have apertures through which the central parts of the rollers'project.

5. The combination in a caster, of a base provided with a dat annular raceway; a

swivel section pivoted to the base and having two annular beveled raceways; a series of rollers located between the base and the swivel section, each roller having a main cylindrical portion and tapered trunnions, rsaid trunnions resting upon the beveled raceways, the base havin a central depend,

ing flange forming a bal raceway; and a series of balls between' said depending flange and the side of the inner beveled raceway of the swivel section. i

6. The combination in a caster, of abase having a central de ression in which isa central opening, saidp base having an annular Hat raceway; a swivel section; a wheel carried thereby, said swivel section havin a body portion located under the base and having a central boss extending through the central openin in the base; a bolt extending through t e said boss and prevented from turning therein, said bolt having an enlarged lhead overlapping the bottom of the depression of the base; a nut on the bolt; a series of balls between the base and the swivel section for taking the lateral thrusts upon the caster; and a series of rollers between the base and the swivel section for carrying the load.

' 7. The combination in a caster, of a base having a central depression with an opening therein, a deep riphery and a flat raceway between Athe ange and the depression; a swivel section# a wheel carried thereby, the body of the swivel section having a central boss extending into the opening in thebase; a king 35 bolt connecting the swivel section and the base, the body of the swivel section having two annular raceways spacedA apart by a deep channel, lsaid raceways being beveled;

a series of rollers, each roller havlng an en- 40 large-d portion bearing against the liat raceway of the base and tapered trunnions bearing on the two raceways of the body portion; means for spacing the rollers; and a ball bearing located between the base and 45 the body of the swivel section for taking the side thrusts of the caster, the deep fla-nge of the base enclosing the mechanism ofthe caster.

J AMES BOWEN.

annular flange at its pe- 30 

